They are each contesting charges of assault and having committed an unlawful act intended to cause bodily harm, in relation to Mr Brown.

The Crown had previously dropped murder charges against the pair.

State forensic pathologist Dr Donald Ritchey gave evidence for the prosecution yesterday and used an anatomical human skull model to show how he had removed the top of Mr Brown's skull to examine his brain.

He said police told him that Mr Brown had been in a physical altercation and had been unresponsive at the scene.

Dr Ritchey said his autopsy concluded that Mr Brown had died from traumatic head injuries sustained during an assault.

North-West Coast man Joshua Myles Looney also gave evidence for the Crown yesterday and said he had not met Mr Brown before seeing him at the hotel on July 17, 2013.

Mr Looney said Mr Brown was aggressive towards him and he had declined Mr Brown's offer of a game of pool.

He said he was "shoved backwards", things happened very fast, then the next thing he remembered seeing was Mr Brown on the ground.

Mr Looney said he struck the pool cue on the ground several times, near Mr Brown's head, because he was frustrated.

Later, after police arrived and he had left the hotel, Mr Looney said a man offered him money and told him, "Tell them I was not there."

Mr Blazely and Mr Dowling are also disputing charges of assault upon Devonport brothers Derryn and Jesse Thomas, arising from the same incident.

Mr Dowling is contesting a further assault charge upon their father Grant Thomas, while Mr Blazely is disputing a charge of grievous bodily harm in relation to the same complainant.

The preliminary proceedings, before bench justice John Boyd, continue today.